U.S. Pat. No. 3,229,928 (Burgess) reports that the industry had to a great extent adopted the use of reels made of plastic to store computer tape. While observing that plastic reels are less expensive, the patent noted that they did not have the strength of metal reels. High strength is needed because of the very substantial load applied by tape wound on the hub of the reel which can be transmitted through the hub to cause the flanges to "toe in" such that the tape may fray against the reel flanges. Burgess' answer to this problem combined plastic flanges with an aluminum hub which would provide the strength needed to resist distortion. In his reel, arcuate tongues project from both flanges through arcuate slots in the hub and are bonded together with a quick-drying solvent cement. Clearance between the metal and plastic parts provides for differences in thermal expansion (column 4, lines 1-9 and 32-35). U.S. Pat. No. 3,328,907 (Burgess) shows a similar reel. Currently, most computer tape reels have aluminum hubs and plastic flanges.
U.S. Pat. No. 3,346,211 (Gruber) suggests that a plastic hub can be used in spite of its lower strength if the flanges are resiliently connected to the hub in order to isolate the flanges from contractions of the hub under the force of tightly wound tape. The reel of U.S. Pat. No. 3,632,053 (Edwards) has a plastic hub, the tape-receiving portion of which is supported from the spindle-receiving portion by a radially-resilient structure. Only the spindle-receiving portion of the hub is attached to the flanges, thus isolating the flanges from forces compressing the tape-receiving portion. The flanges of both the Gruber and Edwards reels derive minimal support from the hub and thus may vibrate more than do those of the Burgess reels during repeated rapid starting and stopping.
The reel of U.S. Pat. No. 4,044,965 (Posso) has a plastic hub which is intended to have such great resistance to radial forces as to be substantially resistant to compression. Part of the strength of the hub is derived from protrusions on the flanges to which the hub is ultrasonically welded. However, if the Posso hub did contract under unusually large tape-winding forces, this would be transmitted to the flanges and could cause them to toe in excessively.